Montgomery County Probate Records Index for John Houser

Could someone tell me how to get a record from Montgomery County Probate Index?Is it on-line, or do I need to write to them?If so, what is the address.Do not have much luck requesting anything by mail to the Montgomery County Courts. I need to find "1851-1861 Probate Record Index which lists John Houser in Doc. 1, page 275" or any other court record for John Houser b: 1816 MD d: 1872 Montgomery Co.He is buried in Miamisburg, OH, Hillgrove Cemetery.Have been unable to get any record for him but know he lived in Preble and Montgomery Co., after moving there from MD with his wife Sarah Drill Houser.